I. Nucleic Acid Sequencing
Initial attempts to determine the sequence of a DNA molecule were extensions of techniques which had been initially developed to permit the sequencing of RNA molecules (Sanger, F., J. Mol. Biol. 13:373 (1965); Brownlee, G. G. et al., J. Mol. Biol. 34:379 (1968)). Such methods involved the specific cleavage of DNA into smaller fragments by (1) enzymatic digestion (Robertson, H. D. et al., Nature New Biol. 241:38 (1973); Ziff, E. B. et al., Nature New Biol. 241:34 (1973)); (2) nearest neighbor analysis (Wu, R., et al., J. Mol. Biol. 57:491 (1971)), and (3) the “Wandering Spot” method (Sanger, F., Proc. Natl. Acad. Sci. (U.S.A.) 70:1209 (1973)).
The most commonly used methods of nucleic acid sequencing are the dideoxy-mediated chain termination method, also known as the “Sanger Method” (Sanger, F., et al., J. Molec. Biol. 94:441 (1975); Prober, J. et al., Science 238:336-340 (1987)) and the “chemical degradation method,” also known as the “Maxam-Gilbert method” (Maxam, A. M., et al., Proc. Natl. Acad. Sci. (U.S.A.) 74:560 (1977), both references herein incorporated by reference).